The El Tigre archaeological site (39°46′49″ S; 62°22′32″ W) is located in the south of Provincia de Buenos Aires, Argentina, on an ancient delta of the Río Colorado. Its sedimentary sequence shows periods of landscape stability and soil formation processes during the period ca. 1,000–400 years bp. The aim of this paper is to investigate the evolutionary history of the vegetation in order to understand palaeoenvironmental changes during the late Holocene. The study of microremains, mainly phytoliths, from the sedimentary sequence indicates that cold and dry conditions predominated at 2,700–2,200 cal bp, from deposition of non-pedogenetic, aggradational sediments in arid or semi-arid environments and/or sparse vegetation cover. Then the climate became much warmer at ca. 2,200–1,200 cal bp, with greater availability of moisture and the presence of xerophytic shrubs and halophytic grasslands, and also extra-regional trees and shrubs. The records indicate that for ca. 1,500–300 cal bp the climate conditions changed to temperate with periods of greater water availability and the presence of a saline steppe and a greater abundance of Monte-Caldenal scrub vegetation elements. This climatic trend is also in agreement with the soil formation processes defined in the archaeological site sequence. The upper layers of the El Tigre site show lower temperatures in the last 300 years, accompanied by variations in the availability of moisture, with alluvial processes characterized by the presence of saline grasslands with xerophytic shrubs and an increase in Asteraceae and Poaceae, continued by the recent top samples with ruderal communities and sandy grasslands.

El Tigre考古遗址（南纬39°46′49″；西经62°22′32″）位于阿根廷布宜诺斯艾利斯省的南部，在科罗拉多州的一个古老三角洲上。它的沉积序列显示了ca期间的景观稳定时期和土壤形成过程。1,000–400年基点。本文的目的是研究植被的演化历史，以了解全新世晚期的古环境变化。从沉积序列研究的微残余物，主要是植物石，表明在干旱或半干旱环境和/或稀疏植被中，非成岩，凝集性沉积物的沉积在2700-2200 bp bp的寒冷和干燥条件下占主导地位。然后，气候变暖了大约。2,200–1,200卡路里bp，具有更多的水分供应，并且有旱生灌木和盐生草原，还有区域外的树木和灌木。记录表明，约。在1,500–300 cal bp的气候条件下，随着可用水量增加和盐碱草原的出现以及蒙特卡德纳勒山的丰度增加，温度逐渐变温。擦洗植被元素。这种气候趋势也与考古现场序列中定义的土壤形成过程一致。El Tigre站点的上层在过去300年中表现出较低的温度，伴随着水分供应的变化，冲积过程的特征是存在盐渍草原和旱生灌木，菊科和禾本科的增加，随后近期有rurudal社区和沙质草地的主要样本。